Adjusting mechanism for automobile brake shoes



Dec. 30, 1941.

ADJUSTING MECHANISM FOR AUTOMOBILE BRAKE SHOES Filed Aug. 4, 1940 2Sheets-Sheet l fg 27a, a, 32 /5 a3 35 45 /5 [fave/Zier a a .n .a7

G. BENDER v 2,268,275

Dec. 30, 1941. G, BENDER 2,268,275

ADJUSTING' MECHANISM FOR AUTOMOBILE BRAKE SHOES Filed Aug. 4, 1940 2Sheets-Sheet 2 Patented Dec. 30, 1941 UNITED STATES PATENT OFFICEADJUSTING IHECHANISM FOR AUTOMOBILE BRAKE SHOES 10 Claims.

This invention relates to new and useful improvements in brake shoeadjusting mechanisms for automobiles.

Among the main objects of the invention is the provision of a mechanismwhich is simple to install, which increases the braking efciency, andprolongs the life of the brake lining, and which can be easily adjustedand does not require special tools.

Another object f the invention is to provide an adjusting mechanism forbrake shoes which is accurate and efcient in operation, provides smoothbraking operation, and which energizes both brake shoes in forward andreverse operations and insures even wear on both brake shoes.

Another object of the invention is to provide an adjusting mechanism forbrake shoes which is enclosed in a box or housing to protect it from mudand sand and ice and to maintain it lubricated at all times.

Still another object of the invention is to provide a brake shoeadjusting mechanism which can be easily and quickly installed, does notrequire drilling or other machine operations, and can be applied tobrake mechanisms of the type now in use.

With these and other objects in View, my invention consists in certainnovel features of construction and arrangement of parts, hereinaftermore fully described and claimed, and illustrated in the accompanyingdrawings, in which- Figure l is a front elevation of the braking plateand the brake shoe mechanism mounted thereon.

Figure 2 is a rear elevational View thereof.

Figure 3 is an enlarged cross section taken longitudinally and.vertically through the adjusting mechanism.

Figure 4 is a cross section taken on line fl-fl of Figure 3.

Figure 5 is an enlarged cross section taken on line 5-5 of Figure 4.

Figure 6 is a vertical cross section taken on line 6-6 of Figure 5.

Figure 7 is an enlarged end view of the front adjusting screws.

Figure 8 is an enlarged end view of the head of said adjusting screw.

Figure 9 is an enlarged end view of the head of the other adjustingscrew.

Figure 10 is an enlarged longitudinal and vertical cross section througha modied form of my adjusting mechanism.

Figure 11 is an enlarged end View of the inner end of the front brakeshoe adjusting member.

Figure 12 is an enlarged end view of the adjusting screw.

Figure 13 is a vertical and longitudinal cross section of anothermodified form of my adjusting mechanism.

Figure 14 is a vertical cross section taken on line I-III of Figure 13.

Figure 15 is an elevation of one of the brake shoe washers.

Referring by numerals to the accompanying drawings, II! indicates theannular flange of a brake drum and II the braking plate or flange onwhich the brake shoes and the adjusting mechanism are mounted.

This plate has a central opening I2. A pair of brake shoes I4 isarranged to operate against the internal surface of flange Ill. Thesebrake shoes are operatively associated at one of their ends, the lowerends Ila, in the present instance, with an actuating member I5 of abrake operating mechanism. A return brake shoe spring I6 is arranged toone side of central opening I2 and extends between the brake shoes I4and is connected at its ends to the respective brake shoes near saidends Illa.. A similar coiled spring II is arranged on the opposite sideof said opening IE and is connected at its ends to the respective brakeshoes near the upper ends I4b thereof. All of the above describedmechanism is of usual construction and operates in the usual manner,springs I6 and Il being used to hold the brake shoes in contracted orinoperative positions and member I5 being operable to move said brakeshoes against the iniuence of said springs into braking engagement withthe rim I0.

My adjusting mechanism is arranged in a box or housing I8 which is fixedin position on flange II between the ends |419 of brake shoes I4 bymeans of bolts I9.

These bolts are passed through openings a1- ready formed in flange IIand are screw-seated in apertures 20 in box I8. Since my adjustingmechanism is to be used on automobiles already in use, the presentadjusting brackets furnished with the car are removed from plate II andthe box I8 is installed in its place, the openings 2U being spaced tocoincide with the apertures formed in the plate I I.

This box I8 is formed with a chamber 2I which opens on the inner side orthat side placed against the plate II, as indicated at 22. This openingcoincides with an opening 24 formed in said plate II. If desired, aflange 23 can be formed on box I8 to extend outwardly and t into theopening 24. A plate or cap 25 is held in position on ilange II by one ofthe bolts I9 and is used to close said opening 24 and chamber 2 I.

The front and rear walls |8a and |819, respectively, of housing I8 areeach extended or thickened and formed with a longitudinally disposedbore 26. Slidably arranged in the bore of the forward end |8a is asleeve 21. The outer or forward end of this sleeve is enlarged, asindicated at 21a, and is formed with a pair of spaced vertically andlongitudinally disposed ears 28. The head 21a forms a stop and limitsthe inward movement of sleeve 21. A pin 29 is slidably arranged insleeve 21 and the outer end of this pin terminates in a head 30operating between ears 28. This head is formed with a verticallydisposed slot 3I which receives the end |412 of the secondary brake shoeI4. Head 30 is formed with at sides 38a which bear against ears 28 andthus prevent the rotative movement of sleeve 21, the pin 29 being heldagainst rotative movement by its engagement with the secondary brakeshoe I4.

The pin 29 extends about one-half the distance of sleeve 21. The outeror inner half of the bore of said sleeve is screw-threaded and receivesthe right hand screw 32. The end of this screw is formed V-shaped incross section, as indicated at 34, and engages one of a plurality ofV-shaped grooves 35 formed diametrically in the corresponding end of pin29 (see Figs. 6 and '1).

Screw 32 extends into chamber 2| and terminates in a hexagonal head 36.The face of this head is formed with an axially disposed bore 36a and aplurality of radially disposed V-shaped grooves 361: (see Fig 8). Ahexagonal head 31 is formed on one end of a screw 38 and the face ofthis head is formed with an axially projecting pin 31a which is freelyreceived in bore 36a and is also formed with a plurality of V-shapedprojections or teeth 3'ib radially disposed on said face and engagingthe V-shaped notches or grooves 36h of head 36. hand screw thread and isscrew-seated in a bore 39 formed in the inner end of a pin or brake`shoe rod 40. The latter is slidably mounted in a bore 4I formedlongitudinally in the end wall |817 of housing I8.

The outer end of this pin is formed with a vertically disposed slot 46awhich receives the upper end I 4b of the primary brake shoe I4.

A coiled spring 42 is connected at one end to the secondary brake shoeI4 and at the other end to box I3. Thus said spring acts on pin 29 andholds it in engagement with screw 32,

The .screws 32 and 38 are interlocked or interengaged by means of theV-shaped notches 36h and V-shaped projections 31h. Thus said screwscannot be operated accidentally to disturb their adjusted positions.However, said screws can be operated independently of each other byholding one of the screw threads stationary and actuating the head ofthe other screw. In doing so the adjusting screws are forced apartagainst the tension of springs 42 and I1 to allow the V-shaped teeth orprojections to ride over the high points between the notches.

To adjust the secondary brake shoe I4, lefthand screw 38 is heldstationary by applying a wrench to head 31 thereof, and righthand screw32 is adjusted by another wrench applied to head 36. To tighten thesecondary brake shoe, head 36 is turned upwardly, as indicated at solidar- Screw 38 has a leftl rows, and to loosen said brake shoe, the head36 is turned downwardly, as indicated by dotted arrows.

To adjust the primary brake shoe I4, righthand screw 32 is heldstationary and lefthand screw 38 is turned. To tighten the primary brakeshoe, head 31 of screw 38 is turned upwardly, as indicated by solidarrows, and to loosen the primary brake shoe, the head 31 is turneddownwardly, as indicated by dotted arrows.

Chamber 2| may be filled with oily waste, as indicated at 43, in orderto keep the adjusting mechanism lubricated.

In the modified form shown in Figures 10 to 12, inclusive, a pair ofb-rake shoe adjusting rods 44 and 45 are slidably mounted in the endwalls of a housing 46. Adjusting rod 44, which engages the secondarybrake shoe, has its inner end 41 formed with an axial bore 48 in whichis received a pin 49 projecting from the end 50 of adjusting member 5I.The face of end 41 is provided with a plurality of radially disposedV-shaped notches 41a and the face of end 50 is provided with a pluralityof radially disposed V-shaped teeth or projections 50a which fit intosaid notches and hold members 44 and 5I against accidental rotation.

The other end of member 5I is formed with a screw-threaded extension 52which is screwseated in a screw-seated bore 53 of rod 45, the latterengaging the primary brake shoe. Thus by turning the adjusting member 5|in proper direction the rods 44 and 45 can be extended or retracted totighten or release the brake shoes. Member 5| is provided with ahexagonal head 5Ia to permit engagement thereof by a wrench.

The inner end of rod 45 is formed with an external screw thread forreceiving a stop nut 54 and a lock nut 55. The nut 54 bears against therear end wall of the housing and limits the rearward movement of theadjusting mechanism, the tension of the spring 42 urging said parts inthis direction.

In the form shown in Figures 13 and 14 a pair of adjusting rods 56 and51 is slidably mounted in the end walls of a housing 58. The inner endof the front rod 56 is provided with a longitudinal bore 59 in which isloosely disposed a pin 68 of an adjusting member 6|. This member has ahexagonal head 62. The opposite end of member 6| has a screw extension63 engaging a screw-threaded bore 64 formed in the inner end of rear rod51. Thus by turning the head 62 in proper direction rods 56 and 51 canbe moved outwardly or inwardly. A spring member 65, in the form of athin steel rod, extends transversely and vertically through the housingand has its ends secured in the top and bottom walls thereof. Thismember bears against one of the flat faces of the head 62 and holds theadjusting member against accidental rotative movement and at the sametime permitting movement of said member by a suitable tool. The outerend of rod 56 is provided with an external `screw thread, as indicatedat 56a, and receives a stop nut 66 and a lock nut 61. Stop nut 66 bearsagainst the front end wall and limits the rearward movement of theadjusting mechanism.

In order to prevent Wear of the heads and rods, such as 30 and 40,respectively, at points of engagement with the ends I4b of the brakeshoes, I provide replaceable washers 68 at said points. Each of thesewashers is adapted to be slipped over the respective head or rod. Eachwasher 83 is provided with a diametrically disposed portion 69 which isadapted to lenter thel slot 3|of head S-or sloty 40a of rodr 40, asthecase may be, and form a bearing surface for the end |41) of therespective brake shoe. Thus the bottoms of slots 3| and 40a are therebyprotected against` wear. As the portions 59 wear out, the washers S8 canbe easily and economically replaced. Furthermore, washers 68 can be madeof vvarious thicknesses to suit the Conditions. These washers 63 can beused equally as well with the modied forms shown in Figures 10 and 13.

To adjust the brake shoe of the form shown in Figures 1 to 9, each screwis moved away from each other, so as to bring the brake Shoes tightlyagainst the drum. Then the wrench is brought into engagement with theheads of both screws, and the wrench is moved downward, as indicated bydotted arrows in Figures 8 and 9. Thus both brake shoes are movedsimultaneously inward so as to obtain proper operating clearance betweenthe brake shoe and the drum.

When the brake mechanism is actuated, the brake shoes are applied to thedrum by the operation of members I5, the brake shoes being moved outwardtoward the drum and against the inuence of springs I5 and Il. Upon therelease of the brake mechanism, the brake shoes are contracted or movedaway from the drum by the action of said springs. As the drum rollsforward, as indicated by arrow in Figure 1, during the forward movementof the vehicle, there is a tendency upon the release of the brakemechanism to move the primary shoe away from the drum, While in the caseof the secondary shoe there is a tendency to retain said shoe inengagement with the drum. The auxiliary spring 42 connected at one endto the secondary brake shoe and at the other to the casing I8 has thetendency to pull said secondary brake shoe inward and away from thedrum.

I claim:

l. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally disposed brake shoe pins slidably mounted in said housingin opposed relation to each other and having their outer ends adapted toengage the corresponding ends of a pair of brake shoes, a screw memberinterposed between and having its ends engaging the inner ends of saidpins and operable to adjust said pins inward and outward relatively tosaid brake shoes, said screw member having a polygonal head, and a pinsecured at its ends to said housing and extending at right angle to saidhead and in contact with one of the sides thereof for locking said screwmember against accidental rotation and permit manual rotation of saidhead against the tension of said pin.

2. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally disposed brake shoe pins slidably mounted in said housingin opposed relation to each other and having their outer ends slottedadapted to engage the corresponding ends of a pair of brake shoes, ascrew member interposed between the inner ends of said pins and operableto adj-ust said pins inward and outward relatively to said brake shoes,and a replaceable washer arranged on the slotted end of each pin andhaving a diametrical portion disposed in the slot of the pin to providea bearing surface for the end of each corresponding brake shoe.

3. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally disposed screw member interposed'between the inner endsf ofsaid pins and operable to adjust saidpins inward'andoutward relativelyto said brake shoes,

and alwasher arranged on'the outer end of each pin and having adiametrical portion engaging the slot thereof to provide a bearingsurface `for the corresponding brake shoe whereby saidpin is protectedagainst wear and said washer can be replaced when worn.

4. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally disposed and axially aligned pins slidably mounted in theend walls of said housing and having their outer ends adapted to engagethe corresponding ends of a pair of brake shoes, and a pair of screwsscrewseated in the inner ends of said pins and having their headsnormally interlocked to prevent independent rotation, said screws beingoperable manually independently of each other.

5. A brake mechanism comprising a housing, a pair of horizontallydisposed coaxial pins slidably mounted in said housing and having theirouter ends adapted to engage the corresponding ends of a pair of brakeshoes, each of said pins having its inner end internally screw-threaded,a screw screw-seated in the inner end of each pin, the heads of saidscrews abutting each other, one of said heads being formed with ahorizontal bore and the other head with a projecting pin revolublyseated in said bore, and means for interlocking said heads to preventaccidental rotation of one screw relatively to the other.

6. A brake shoe adjusting mechanism comprising a housing having spacedend walls, a pair of horizontally and coaxially disposed pins slidablymounted in said end walls, a head slidably mounted in one of said pinsand having a bifurcated outer end for engaging the free end of a brakeshoe, a pair of opposed screws screwseated in the inner ends of saidpins, one of said screws bearing against the inner end of said head foradjusting the latter longitudinally relatively to its pin.

'7. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally and coaxially disposed pins slidably mounted in therespective end walls of said housing, bifurcated means at the outer endof each pin for engaging the upper ends of a pair of brake shoes, a wearmember removably arranged on each bifurcated means to receive the wearfrom said brake shoe ends, a pair of opposed screws screw-seated in theinner ends of said pins and having their heads in cooperating relationwith each other, whereby said screws can be manually actuatedindependently or cojointly to adjust said brake shoes.

8. A brake shoe adjusting mechanism comprising a housing, a pair ofhorizontally and coaXially disposed pins slidably mounted in therespective end walls of said housing, bifurcated means at the outer endof each pin for engaging the upper ends of a pair of brake shoes, a wearmember removably arranged on each bifurcated means to receive the wearfrom said brake shoe ends, a pair of opposed screws screw-Seated in theinner ends of said pins and having their heads in cooperating relationwith each other, whereby said screws can be manually actuatedindependently or cojointly to adjust said brake shoes, and meanscooperating with the heads of said screws for preventing accidentalrotation of the latter.

of each pin for engaging the upper end of eaclr. of a pair of brakeshoes.

10. In a brake shoe adjusting mechanism, the combination with a slidablepin having a bifur cated outer end for engaging the free end of.l abrake shoe, of a washer having a diametrical portion for engaging theslot of said bifurcated end and forming a bearing surface for said brakeshoe end.

GEORGE BENDER.

